Control means for dishwashing machines and similar washing apparatus



April 16, 1957 A. JQA. ASPLUND 2,738,789

CONTROL MEANS FOR DISK- WASHING MACHINES AND SIMILAR WASHING APPARATUS Filed May 31, 1955 Fig; 1

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United States Patet 2,788,789 CONTROL MEANS FOR .olsnwasnmo M CHINES AND SIMILAR wAsrnNo APPA- RATUS Ame Johan Arthur Asplund, Bromnia, Sweden Application May 31, "1955, Serial Ne. 512,069

Claims. c1. muss This invention relates to washing apparatus and more particularly to dishwashing machines and similar apparatus comprising an impeller member driven by an electric motor and adapted to circulate dishing liquid against objects to be dished, a switch for said motor, a valve for supply of said liquid, and a control member adapted, upon a loading movement in one direction, by a continuous movement in the opposite direction without any actuation by the motor to operate the machine so as automatically to perform a washing cycle including one washiiifg step and at least one rinsing step and means to drain 'ofi dishing liquid between said steps.

One main obect of the invention is to provide control means adapted in a simple and reliable manner to control the duration of each of said steps.

A further object of the invention is to provide a control means adapted in a simple and reliable manner to control the duration of each'of said steps and also to accomplish a relative displacement of the periods during which the motor operates and the valve admits washing liquid to be supplied during the individual steps.

Further objects and advantages of the invention will become apparent from the following description cons'idered connection with the accompanying drawing which forms part of this specification and of which:

Fig. l is a longitudinal sectional view of a control device constructed according to the invention and comprising a. switch and a valve, said switch being represented in a position interrupting an electric circuit and the valve in [closed position. I

Fig. 2 is the same view as illustrated by Fig. 1 but presenting the switch in the position closing the circuit and the valve in open :position.

Fig. 3 is a perspective view of a cam actuating the switch alnd the valve. g V

Referringto the drawing, denotes a valve housing formed as'a longish body having a straight wall 12 limiting a chamber 14 disposed in said body and having its base provided with 'a projecting portion 16. Said portion 16 has a conical recess 18 adapted to house a correspondingly shaped conicalvalve body 20 preferably made of rubber. Said valve body has a bare plate 22 made of the same material and extending beyond the chamber 14 and 'with a circumferential edge being kept in sealing contact and 36,-respectively, with the chamber 28 provided-in the ice cover 24. The lower space I 32 further communicates through a fine channel 38 with a larger enamel 0 previded in the body 10 and extending between are ber 14 and a 't'ransver'saily ''itending feeding duct 42 "connected in suitable manner "to a supply pi e 44, A "needle valve is located between the channels 40 ahd '42 within a prolongation of the channel 40, said 'iieedle' valve coinprising a needle 46 carried by ascrew 48 aiid by means of said screw adjustable relatively a seat 50. The 's'few 48 is accessible from outside by being located in a threaded bore '52 closed by means of a screw seal '54. The upper minor "s'p'a'ce 30 is provided with a valve 56 by means of which said space is adapted to be brought into and out of communication with a room 58 formed at one end of the body 10. Said body further has a chann'el 60 opening into the bottom of the conical valve seat 18 and continuing by a prolongation tube 62 located outside said body and with a play entering a discharge tube 64 projecting from the wall of the room 58 and communicating through said play with said room.

For control of the valve 56 opening in a direction towards the space 30, a pivoted arm 66 is disposed in the room 58. Said arm 66 is adapted to pivot around a shaft 68 and has its one end connected to the inwardly opening valve body of the valve 56 and its opposite end formed with a forked portion 70 projecting outside said room 5%. The forked portion 70 is engaged by a transverse rack member 72 adapted to be longitudinally dis placed against the pressure of a spring (not shown) and to be adjusted with regard to its axial position relatively to the forked portion 70 by means of nuts 74 provided on either side of said portion. The rack member 72 carries at its one end a fork 76 supporting a rotatably mounted wheel 78 rolling on a body 80 formed with peripheric cams and adapted to rotate in a plane substantially vertical relatively to said rack member. Said cam 80 is actuated to rotate by means of diagrammatically'shown timing means 82, which are set to operate preferably by means of a lever arm 84 loading a spring driving said timing means, said lever arm 84 in the embodiment shown being connected to the body of said cam 80. The end of the rack member 72 remote from the fork 76 is formed to contact the periphery of a wheel-86 rotatably mounted in a fork 88 secured to one end of a blade spring 96 the opposite end 94 of which is secured to the casing of a switch 92. Said switch is suitably a so called micro-switch. The spring 90 is formed between itsend 94 and the fork 88 so as to actuate the breaker 'pin'96 of the switch.

The control device described hereinbefore which is intended to be fitted to a dishwashing machine, for example of the type disclosed in the United States patent to S. B. F. Carlstedt No. 2,684,921, dated July 27, 1954, has its supply tube 44 connected to a water'conduit and its discharge tube 64 to the liquid container of the dishwashing machine. The switch 92 is included in the electric circuit for the electric motor drivingthe impeller member of the machine.

The device constructed according to this invention operates in the following manner. When starting a dishwashing cycle the cam 80 either by means of the lever arm 84 or by means of 'a key notshown and fitting to a square barprojecting from the timing'means 82 is turned .over a predetermined and adjustable-angle,-for"example from the position shown in Fig, l to that illustrated "in Fig. 2. By this movement the spring of the timing means is loaded-and the wheel 78 cau'sed 'to-rollover the guidscribed above.

ing surface of the body 80, upwardly to stay on the elevated portion 100. Hereby the rack member 72 is dis- 'a pressure produced in the chamber 28 of the cover 24 by water streaming from the water conduit through the water supply conduit 'over the passageway throttled by the needle valve 46,59 through the channels 4!) and 38, the space 32 and the channel 36. Said release is efiected through the channel 34 and the space 30 and causes a pressure difference between the water housed in said chamber 28' and that housed in the chamber 14 which results in'a displacement of the valve body 20 from its seat 18 causing water to be passed through the prolongation tube 52 and the discharge tube 64 into the liquid container of the dishwashing machine. Simultaneously the switch .92 closes the electric circuit resulting in that the electric motor is set into operation,

As will be understood from Fig, 3 the body 80 has three elevated faces 100, 102 and 104 and therebetween depressions 196. When the body 80 for control of a washing cycle is caused by the timing means 82 to rotate in the direction opposite to the loading direction set forth above the wheel 78 after a predetermined time will 'roll down into the first depression 196 actuating the valve 56 through the rack member 72 of the pivoted arm 66 so as to be closed and the switch through the Wheel 86, the spring 90 and the breaker pin 96 so as to interrupt the supply of current to the electric motor. As will be readily understood the closing of the valve 56 will result in producing a new pressure in the chamber 28 of the lock 24 causing in turn the valve body 20 to be displaced to the right in the plane of the Figs. 1 and 2 so as to interrupt discharge of water through the tube 62. The water which during the open position of the valve 56 filled the room 58 is removed therefrom by the ejector effect created between the tube 62 and the discharge tube 64. The

continuing movement of the body 80 causes the Wheel 73 to roll upwardly onto a new elevated face 102 resulting in the same manner as described above in a renewed opening of the valve 56 and closing of the current circuit to the motor so as to produce a first rinsing step. A second rinsing step is caused, as will be understood without further elucidation, after an interruption by the subsequent depression 1fi6 through actuation of the wheel 78 by the last elevated surface 134 whereafter the body 80 will be stopped after that the supply of current has been interrupted and that of water closed by the wheel 78 rolling down into the last wide depression 106. The shape of the cams 80 on the body thus determines the number of washing and rinsing steps and through the peripherical extension of the elevated surface 109, 102 and 104 the duration of the individual steps. As will be understood trom Fig 3 the washing step has the longest duration, the rinsing steps having a shorter duration, the individual rinsing steps preferably having equal duration. The duration of the washing cycle can be adjusted by varying the angle of turning of the body 89 when bringing said body into the starting position and simultaneously loading the spring of the timing means in the manner de- It is also possible in a similar manner within each individual step to displace relatively one another the periods during which the motor operates and water is supplied. It is possible, for example, to perform such displacement of said periods so as within one step to continue the supply of water into the liquid container of the machine when the motor has been stopped already in order to wash away from the machine impurities which may have remained therein, prior to the start of the next washing step. a

While one more or less specific embodiment of the invention has been shown and described it is to be understood that this is for the purpose of illustration only and that this invention is not to be limited thereby, but its scope is to be determined by the appended claims.

What I claim is:

l. in a dishwashing machine of the type operated by an electric motor controlled by a switch, a control mechanism including said switch, a valve for permitting the flow of water to the washing chamber of the machine to thereby perform a washing cycle consisting of a washing step and at least one rinsing step with drainage of the water between said steps, a movable control'device adapted to be loaded by movement'in one direction to enable it to be moved in the opposite direction without actuation from the motor, said control device including an element having cam surfaces and also having means for loading the control device, means operated by said cam surfaces and effective to intermittently open the valve and maintain it in open position for predetermined periods, said means being also operative on the switch to close the same and maintain said switch closed during the periods that the valve is in open position.

2. In a machine as provided for in claim 1, wherein the cam-operated means consists of a pivoted arm having one end operated by the cam surfaces and having its other end connected to the valve in a manner to control the opening of the valve.

3. In a dish-washing machine of the type operated by an electric motor controlled by a switch, a valve for permitting the flow of water to the washing chamber of the machine to thereby perform a washing cycle consisting of a washing step and-at least one rinsing step with drainage of the water between such steps, a chamber in which the valve is located, a seat in said chamber against which the valve closes, a supplemental valve for controlling the emergence of water from the Valve chamber behind the valve whereby water pressure at the opposite side of the valve will open the valve to permit the flow of Water into the washing chamber of the machine, a spring-operated control device adapted to be loaded by movement in one direction to enable it to be moved in the opposite direction without actuation from'the motor, said control device including a loading member carrying cam elements, means operated by said cam elements when said loading member is moved by the control device for causing open ing of the supplemental valve and effective to intermittently open it and maintain it in open position for predethe switch and maintain the same in closed position during the periods in which the valve is held open;

4. In a dishwashing'machine operated by an electric motor controlled by a switch, a valve interposed between a source of water supply and the washing chamber of the machine, a chamber in which the valve is mounted, a seat therein against which the valve closes and against which the valve is normally maintained in closed positron, a supplemental valve for permitting reduction of water pressure in the chamber behind the valve to thereby cause the valve to be opened by water pressure against the opposite side of the valve, cam means operative to open the supplemental valve and hold the same open for predetermined periods, spring-controlled means for opcrating the cam means, means carried by said cam means for loading the spring-controlled means and means operated by said cam means for closing the switch and holding the same closed during the periods that the supplemental valve is maintained in open position.

5. in a dishwashing machine of the type operated by an electric motor controlled by a switch, .a control mechanism including said switch, a valve for intermittently permitting the flow of water to the washing chamber of the machine for the performance of a washing cycle, a spring-operated control device'provided with a projection by which the spring of said device is loaded, a rotatable cam coupled to the control device, said cam having a plurality of spaced elevations with depressions between them, a pivoted lever having a roller operative against the cam, said lever being connected to the valve and caused to open the valve during each period that the roller traverses the elevations of the cam and cause clos- 5 ing of the valve when the roller traverses the depressions, switch-operating means connected to the lever and caused to maintain the switch in open position while the roller is in the cam depressions and close the switch while the roller traverses the cam elevations, whereby the switch 10 will be closed to operate the electric motor during periods that the valve will be open.

References Cited in the file of this patent UNITED STATES PATENTS Merseles Apr. 20, 1926 Lundberg July 3, 1934 Hutchings Sept. 22, 1936 Clark Nov. 20, 1951 

